对Oracle进行故障排除 - 挂起进程

Question

我正在尝试理解我们正在处理的Java进程问题.这个过程已经在生产中运行了大约4个月,本周早些时候它开始悬挂.当我查看进程的线程转储时,所有相关线程(3)都有如下堆栈:

    "TxnParser_1" prio=6 tid=0x69bd3400 nid=0x2534 runnable [0x6aa2f000]
   java.lang.Thread.State: RUNNABLE
        at java.net.SocketInputStream.socketRead0(Native Method)
        at java.net.SocketInputStream.read(SocketInputStream.java:129)
        at oracle.net.ns.Packet.receive(Unknown Source)
        at oracle.net.ns.DataPacket.receive(Unknown Source)
        at oracle.net.ns.NetInputStream.getNextPacket(Unknown Source)
        at oracle.net.ns.NetInputStream.read(Unknown Source)
        at oracle.net.ns.NetInputStream.read(Unknown Source)
        at oracle.net.ns.NetInputStream.read(Unknown Source)
        at oracle.jdbc.driver.T4CMAREngine.unmarshalUB1(T4CMAREngine.java:1099)
        at oracle.jdbc.driver.T4CMAREngine.unmarshalSB1(T4CMAREngine.java:1070)
        at oracle.jdbc.driver.T4C8Oall.receive(T4C8Oall.java:478)
        at oracle.jdbc.driver.T4CStatement.doOall8(T4CStatement.java:207)
        at oracle.jdbc.driver.T4CStatement.executeForDescribe(T4CStatement.java:790)
        at oracle.jdbc.driver.OracleStatement.executeMaybeDescribe(OracleStatement.java:1039)
        at oracle.jdbc.driver.T4CStatement.executeMaybeDescribe(T4CStatement.java:830)
        at oracle.jdbc.driver.OracleStatement.doExecuteWithTimeout(OracleStatement.java:1132)
        at oracle.jdbc.driver.OracleStatement.executeInternal(OracleStatement.java:1687)
        at oracle.jdbc.driver.OracleStatement.execute(OracleStatement.java:1653)
        - locked <0x40e22f88> (a oracle.jdbc.driver.T4CStatement)
        - locked <0x28f8d398> (a oracle.jdbc.driver.T4CConnection)
        at com.gcg.data.LogParsingInfo.initFromDB(LogParsingInfo.java:262)
        at com.gcg.om.OmQueueEntry.initParseInfoFromDB(OmQueueEntry.java:104)
        at com.gcg.om.GenericQueueEntry.run(GenericQueueEntry.java:237)
        at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:886)
        at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:908)
        at java.lang.Thread.run(Thread.java:619)

没有线程等待锁定,因此进程没有死锁.这些正在完成工作的3个线程只是被阻塞等待Oracle的响应,至少这对我来说是这样的.

看看Oracle,当我查询v $ session时,看起来与这些线程关联的一个连接当前正在执行查询,尽管我看不到sql.

select ... from v$session where ...;
SQL_ADDRESS      SQL_HASH_VALUE SQL_ID        SQL_CHILD_NUMBER SQL_EXEC_START SQL_EXEC_ID PREV_SQL_ADDR    PREV_HASH_VALUE PREV_SQL_ID   PREV_CHILD_NUMBER PREV_EXEC_START PREV_EXEC_ID
---------------- -------------- ------------- ---------------- -------------- ----------- ---------------- --------------- ------------- ----------------- --------------- ------------
              00              0                                                           0000000239F59EE8      1483377872 fqr8pndc6p36h                 5 26-JUL-12           32080545
              00              0                                                           0000000239F59EE8      1483377872 fqr8pndc6p36h                 5 26-JUL-12           32080546
0000000148CABD88     1784444892 a16hxxtp5sxyw                                             0000000239F59EE8      1483377872 fqr8pndc6p36h                 5 26-JUL-12           32080544

select * from v$sql where sql_id = 'a16hxxtp5sxyw';

no rows selected

我的问题是:

1. 在我的分析中,我是否正确该过程被阻止等待Oracle的响应？
2. 我应该在Oracle中寻找什么来理解为什么这个过程会阻塞？

更新:

根据有关查看DBA_WAITERS和DBA_LOCKS的注释

select * from dba_waiters;

no rows selected

select * from dba_locks where BLOCKING_OTHERS <> 'Not Blocking';

no rows selected 

dba_locks中有98行,但由于所有都是'Not Blocking',我不认为这是一个锁定问题？这个过程已经处于这种状态超过3个小时,因此现在已经检测到任何死锁.

我认为Oracle实例不是"健康"的理论,但我不知道该看什么.我有一个请求重启Oracle服务器,但还没有完成.

后续问题:v $ session中包含v $ sql中不存在的sql_id是否正常？如果是,在什么条件下？

Answer 1

问题已解决,答案恰好在v $ session表中.显然,Oracle会话可以阻止除锁定之外的其他原因.请注意列FINAL_BLOCKING_SESSION - 它标识作为阻塞的根本原因的会话.我们调查了会话845,发现客户端进程(由MACHINE和PORT标识)不再存在.DBA杀死会话845并且全部恢复正常.

SID     SERIAL# STATUS    PROGRAM          TYPE SQL_ID        PREV_SQL_ID    BLOCKING_SESSION_STATUS BLOCKING_INSTANCE BLOCKING_SESSION FINAL_BLOCKING_SESSION_STATUS FINAL_BLOCKING_INSTANCE FINAL_BLOCKING_SESSION EVENT
------- ------- --------- ---------------- ---- ------------- -------------- ----------------------- ----------------- ---------------- ----------------------------- ----------------------- ---------------------- ----------------------------
 108    22447   ACTIVE    Gcg log parser 1 USER               fqr8pndc6p36h  VALID                   1                 1581             VALID                         1                       845                    library cache: mutex X
 639    40147   ACTIVE    Gcg log parser 3 USER               fqr8pndc6p36h  VALID                   1                 1581             VALID                         1                       845                    library cache: mutex X
 742    34683   ACTIVE    Gcg log parser 2 USER a16hxxtp5sxyw fqr8pndc6p36h  VALID                   1                 1581             VALID                         1                       845                    library cache: mutex X